On Thu, 8 Nov 2001 14:12:23 +0100, you wrote: >can anyone comment on the quality of the Kiron MC-7 teleconverter. >It's supposed to be a 2x 7 element teleconverter. >
I have a Kiron MC-7 2x 7-element TC. It's manual focus. It's a good TC, but there are a couple of under-$100 teleconvertors I like better. I compared several TC's against each other a few months back, using two different lenses. the first lens was the Tokina AT-X SD 300/2.8, focused at a bird-shooting distance of twenty-one feet. The second lens was the Pentax 200/2.5 at a slightly shorter distance. Both lenses were used wide open, at f4, and at f8 - using the aperture ring to select the aperture. The clear winner was the Pentax 1.7x AF Adaptor, followed closely by the Vivitar 2x Macro Focusing TC, then the Kiron 2x TC. The Vivitar and Kiron were very good from f4 on; the Pentax was excellent wide open on the Tokina, and excellent from f4 on the Pentax 200/2.5. The Vivitar was visibly sharper than the Kiron at all apertures, but not by much. After careful comparison and self-tests, I now only use the Pentax 1.7x AF Adapter with my 300/2.8 and 200/2.5, except when I want the built-in extension of the Vivitar macro TC. The Kiron MC-7 is sitting idle, mostly because the other two teleconverters are slightly better. I also tested several other TC's which were obviously inferior to the three above: Albinar 2x Macro Focusing TC; Phoenix 1.7x AF TC (it's a re-badged version of a Kenko); and Kiron 1.5x TC. These teleconvertors are not exactly worthless, they just are not in the same league as the AF Adapter, the Vivitar Macro, and the Kiron 2x when tested on the lenses mentioned above. -- John Mustarde - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
